NEW YORK (TheStreet) -- Apple (AAPL) stock is slumping 1.33% to $93.57 in early-afternoon trading on Friday after billionaire activist investor Carl Icahn told CNBC yesterday that he sold his entire stake in the iPhone maker, citing the risk of China's attitude toward the company.

Icahn previously owned nearly 1% of Apple's outstanding shares, and first disclosed his stake almost three years ago.

He sees a risk in Apple's relationship with China, which made his investment in the company no longer a "no-brainer," Icahn told CNBC. China recently shut down Apple's iBooks Stores and iTunes Movie services in the country.

"You worry a little bit - and maybe more than a little - about China's attitude," Icahn told CNBC, later mentioning that China's government could "come in and make it very difficult for Apple to sell there... you can do pretty much what you want there."

But Icahn mentioned that if China "was basically steadied," he would buy back into Apple.

Shares tumbled more than 6% on Wednesdsay after Apple reported after Tuesday's market close that second-quarter revenue declined for the first time since 2003 as iPhone sales dropped for the first time ever. The stock fell another 3% on Thursday.

"The market was already weak because oil had fallen a couple of pennies, but Icahn just torched the darned thing," TheStreet's Jim Cramer, portfolio manager of the Action Alerts PLUScharitable trust portfolio wrote in a Real Money article. "He went after a gasoline-soaked stock with Apple, a company drenched with petrol that seemed to be waiting for the match to strike."

Cramer added that Icahn has been too negative about the market recently, so he somewhat discounts his view.

(Apple is held in Jim Cramer's charitable trust Action Alerts PLUS. See all of his holdings here.)

Separately, TheStreet Ratings team rates the stock as a "buy" with a ratings score of A-.

Apple's strengths such as its largely solid financial position with reasonable debt levels by most measures, notable return on equity and expanding profit margins outweigh the fact that the company has had sub par growth in net income.

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.